"Research can be difficult, but you don't have to start from scratch if you follow the clues left by scholars who have gone before you!"
As you conduct your research, you will need to make note of the additional resources (book, book chapter, journal article) you identify in the bibliographies, references, notes and footnotes of the sources you are using. The reason for this? Because this is one of the best ways to further your research.
Keep track of your references! Use a citation management system
Reagen, Chris. 2012. "THE WATER TRANSFERS RULE: HOW AN EPA RULE THREATENS TO UNDERMINE THE CLEAN WATER ACT." University Of Colorado Law Review 83, no. 1: 307-338.
For cases, use Google Scholar or Lexis/Nexis. For legislative materials use Congressional Publications.